分子筛催化剂上二异丙苯的择形催化裂化

通过比较4种不同类型的分子筛 HY,Hβ,HZSM-22,HZSM-5,确定了HZSM-5分子筛对二异丙苯择形催化裂化反应具有良好的性能;同时考察了 HZSM-5分子筛的粒径对二异丙苯择形催化裂化反应的影响,确定了纳米 HZSM-5分子筛对该反应的选择裂化性能最好。考察了反应温度和质量空速对二异丙苯择形催化裂化反应的影响,实验结果表明,在反应压力0.1 MPa、反应温度380℃、质量空速6 h~(-1)的条件下,纳米 HZSM-5分子筛上对二异丙苯的裂化率为93.23%,产物二异丙苯中间二异丙苯的选择性为94.20%,间二异丙苯的收率为75.68%。并经实验发现,用质量分数为0.1%的 La 改性纳米 HZSM-5分子筛可提高 HZSM-5分子筛择形催化裂化二异丙苯反应的稳定性。

Shape-Selective Catalytic Cracking of Diisopropylbenzenes over Molecular Sieve Catalysts

Diisopropylbenzenes (DIPBs) are available by-products from synthesis of cumene by alkylation of benzene with propylene.DIPBs shape-selective catalytic cracking were investigated over four different types of molecular sieve catalysts,namely HY,Hβ,HZSM-22 and HZSM-5.HZSM-5 molecular sieve is the most efficient catalyst for the reaction.In experiments of comparing effects of different grain sizes of HZSM-5 on the reaction,nano-HZSM-5 molecular sieve catalyst exhibits the highest cracking rate and selectivity to para-DIPB.Temperature and WHSV on the reaction were investigated.Under optimized conditions;reaction pressure 0.1 MPa,reaction temperature 380℃, WHSV 6 h~(-1),cracking rate for para-DIPB reaches 93.23% ,selectivity to meta-DIPB in product DIPB 94.20% and yield to meta-DIPB 75.68%.When ZSM-5 molecular sieve is modified with 0.1% (mass fraction) of lanthanum,the stability of the reaction improves obviously.